A shari’a classification of hukum (or hukm) which includes all virtuous , recommended, or desirable actions whose fulfillment is rewarded or praiseworthy, but whose negligence will not incur any punishment, blame, or accountability. Such a ruling (hukm mustahabb/ al-hukm al-mustahabb) is not binding (mulzim) in nature, though if properly observed it would be commendable. Mustahabb designates all actions the performance of which is favored over their non-performance. An individual adhering to mustahabb would be worthy of praise, yet would incur no blame or punishment otherwise. An example of mustahabb is charity (sadaqah) and giving by way of gift (hibah or hadiyyah).

The ruling of mustahabb falls between mubah and wajib. It includes all duties that are commendable and recommended to be fulfilled, nevertheless are not essential; fulfillment of which is rewarded, though non-fulfillment is not punishable.

Mustahabb is synonymous with mandub/ mandoob and the opposite of makruh.